Summary: This role is for a Senior Full-Stack Engineer on a freelance basis, focusing on the implementation of end-to-end ingestion and validation flows for an AI-native Wealth OS. The position requires hands-on ownership of both frontend and backend systems, with a strong emphasis on data-driven solutions. The engineer will collaborate directly with the founders to ensure reliable production code while navigating ambiguity and incomplete data.
Key Responsibilities:
- Implement end-to-end ingestion and validation flows, including frontend state management and backend APIs.
- Work directly with founders to convert non-deterministic inputs into deterministic system behavior.
- Ship reliable code in production environments.
- Handle partial inputs, ambiguity, and correction loops in system design.
- Focus on system- and data-driven solutions rather than UI or design aspects.
Key Skills:
- 5+ years of professional software engineering experience.
- Advanced React + TypeScript expertise, particularly in state-heavy and form-heavy workflows.
- Node.js + TypeScript backend experience, specifically with REST APIs.
- Strong relational data modeling skills, preferably with Postgres or equivalent.
- Experience shipping production systems end-to-end.
- Comfort with ambiguity, edge cases, and incomplete data.
- Ability to consume AI outputs and enforce validation and correctness.
- Experience with AI-integrated products and fintech or high-integrity data domains is a strong advantage.
Salary (Rate): undetermined
City: London Area
Country: United Kingdom
Working Arrangements: undetermined
IR35 Status: undetermined
Seniority Level: Senior
Industry: IT
Company Description WORTH is building an AI-native Wealth OS . We turn fragmented, messy, real-world financial data into structured, validated, and reliable intelligence . Our systems are designed to handle partial inputs, ambiguity, and correction loops without breaking trust or usability. We are operating in stealth and moving from a working prototype to a production-grade platform .
Role Description This is a senior freelance/contract role for a Full-Stack Engineer who lives in the UK, EU, or Israel. You will own the implementation of end-to-end ingestion and validation flows , spanning frontend state management, backend APIs, and data models. This is a hands-on role with real ownership and minimal hand-holding. You will work directly with the founders to convert non-deterministic inputs into deterministic system behavior and ship code that is reliable in production. This role is system- and data-driven , not UI- or design-led.
Qualifications Required 5+ years of professional software engineering experience Advanced React + TypeScript (state-heavy, form-heavy workflows) Node.js + TypeScript backend experience (REST APIs) Strong relational data modeling (Postgres or equivalent) Experience shipping production systems end-to-end Comfort working with ambiguity, edge cases, and incomplete data Ability to consume AI outputs and enforce validation and correctness Strong Advantage AI-integrated products (LLMs, OCR, AI-assisted ingestion) Fintech, wealth, accounting, or other high-integrity data domains Ownership of core systems in startup environments Applications are portfolio-first . Links to systems you owned or shipped are a plus, but not required.
